Abstract
Thermally stable multilayer films of polyimide were prepared on noble metal base electrodes by using the Langmuir-Blodgett technique. Here, the monolayer thickness of the multilayer polyimide Langmuir-Blodgett films was about 0.4 nm. We have examined the electrical properties of Au/PI/Au and Au/PI/Pb-Bi tunnel junctions.
For Au/PI/Au junctions, it was found that we could get ultrathin polyimide Langmuir-Blodgett films having a good electrical insulating property when the number of deposited polyimide layers is greater than about 30. The electrical conduction mechanism through polyimide Langmuir-Blodgett films was concluded to be ruled by the well-known tunneling theory.
For Au/PI/Pb-Bi junctions, typical I-V characteristics of tunnel junctions were obtained at a temperature below the critical temperature of a superconductitg Pb- Bi alloy, when the number of deposited polyimide Langmuir-Blodgett films was 27. It was also concluded that the electrical conduction mechanism through Polyimide Langmuir Blodgett films was ruled by the B. C. S. theory.
From thses experimental results descrided above, we found that polyimide Langmuir-Blodgett films were very useful electrical insulating materials, having a thickness of less than several tens of nm.
